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Duplication of the Xq28 region, involving MECP2 (dupMECP2), has been primarily described in males with severe developmental delay, spasticity, epilepsy, stereotyped movements and recurrent infections. Carrier mothers are usually asymptomatic with an extremely skewed X chromosome inactivation (XCI) pattern. We report a series of six novel symptomatic females carrying a de novo interstitial dupMECP2, and review the 14 symptomatic females reported to date, with the aim to further delineate their phenotype and give clues for genetic counselling. One patient was adopted and among the other 19 patients, seven (37%) had inherited their duplication from their mother, including three mildly (XCI: 70/30, 63/37, 100/0 in blood and random in saliva), one moderately (XCI: random) and three severely (XCI: uninformative and 88/12) affected patients. After combining our data with data from the literature, we could not show a correlation between XCI in the blood or duplication size and the severity of the phenotype, or explain the presence of a phenotype in these females. These findings confirm that an abnormal phenotype, even severe, can be a rare event in females born to asymptomatic carrier mothers, making genetic counselling difficult in couples at risk in terms of prognosis, in particular in prenatal cases.

To assess at a population-based level the frequency with which severe structural congenital malformations are detected prenatally in Europe and the gestational age at detection, and to describe regional variation in these indicators.In the period 1995-1999, data were obtained from 17 European population-based registries of congenital malformations (EUROCAT). Included were all live births, fetal deaths and terminations of pregnancy diagnosed with one or more of the following malformations: anencephalus, encephalocele, spina bifida, hydrocephalus, transposition of great arteries, hypoplastic left heart, limb reduction defect, bilateral renal agenesis, diaphragmatic hernia, omphalocele and gastroschisis.The 17 registries reported 4366 cases diagnosed with the 11 severe structural malformations and of these 2300 were live births (53%), 181 were fetal deaths (4%) and 1863 were terminations of pregnancy (43%); in 22 cases pregnancy outcome was unknown. The overall prenatal detection rate was 64% (range, 25-88% across regions). The proportion of terminations of pregnancy varied between regions from 15% to 59% of all cases. Gestational age at discovery for prenatally diagnosed cases was less than 24 weeks for 68% (range, 36-88%) of cases. There was a significant relationship between high prenatal detection rate and early diagnosis (P0.0001). For individual malformations, the prenatal detection rate was highest for anencephalus (469/498, 94%) and lowest for transposition of the great arteries (89/324, 27%). Termination of pregnancy was performed in more than half of the prenatally diagnosed cases, except for those with transposition of the great arteries, diaphragmatic hernia and gastroschisis, in which 30-40% of the pregnancies with a prenatal diagnosis were terminated.European countries currently vary widely in the provision and uptake of prenatal screening and its quality, as well as the "culture" in terms of decision to continue the pregnancy. This inevitably contributes to variation between countries in perinatal and infant mortality and in childhood prevalence and cost to health services of congenital anomalies.

A female newborn is reported with dextrocardia and a partial trisomy 20q, derived from a t(2;20) paternal translocation. The most discriminating findings of the condition include brachycephaly, bulging forehead, deep set eyes, short nose, large ears, dimpled chin, short neck and a heart defect. Previously reported patients with this rare chromosomal anomaly are reviewed.

OBJECTIVE: To determine the sensitivity of ultrasonography in screening for foetal malformations in the pregnant women of the Swiss Canton of Vaud. STUDY DESIGN: Retrospective study over a period of five years. METHOD: We focused our study on 512 major or minor clinically relevant malformations detectable by ultrasonography. We analysed the global sensitivity of the screening and compared the performance of the tertiary centre with that of practitioners working in private practice or regional hospitals. RESULTS: Among the 512 malformations, 181 (35%) involved the renal and urinary tract system, 137 (27%) the heart, 71 (14%) the central nervous system, 50 (10%) the digestive system, 42 (8%) the face and 31 (6%) the limbs. Global sensitivity was 54.5%. The lowest detection rate was observed for cardiac anomalies, with only 23% correct diagnoses. The tertiary centre achieved a 75% detection rate in its outpatient clinic and 83% in referred patients. Outside the referral centre, the diagnostic rate attained 47%. CONCLUSIONS: Routine foetal examination by ultrasonography in a low-risk population can detect foetal structural abnormalities. Apart from the diagnosis of cardiac abnormalities, the results in the Canton of Vaud are satisfactory and justify routine screening for malformations in a low-risk population. A prerequisite is continuing improvement in the skills of ultrasonographers through medical education.

Since 1988 the epidemiological surveillance of congenital anomalies (malformations, chromosomal aberrations, metabolic diseases, hereditary diseases, neurosensorial defects, etc.) is carried out by the Swiss registry of EUROCAT (European Registry of Congenital Anomalies and Twins). Several Swiss cantons collaborate through their own local registry, transmitting data to the central registry in Lausanne. We present the main objectives and methods of registration and give the global prevalence rates for the main malformations for 1996 and the period 1993-1996.

In the context of the EUROCAT study, data on selected congenital malformations and chromosome aberrations were collected from the Canton of Zurich (1988-1997). It was found that the major proportion of severe and early malformations, such as anencephalus and holoprosencephaly, were detected prenatally; for oral clefts and meningomyeloceles this was not the case, at any rate in regard to isolated (non-syndromic) malformations. However, if these defects occur in combination with a chromosome aberration, the likelihood of such a case being registered is higher. For the same reason, i.e. due to abnormal ultrasound findings and intrauterine growth retardation, trisomies 13 and 18 were more often detected prenatally than trisomy 21.

This article is based on the study of 52 cases of Turner's syndrome, born between 1980 and 1996 and recorded in the Registry of Congenital Anomalies in the Canton of Vaud. In most cases the cytogenetic analysis was based on maternal multiple-marker screening, sonography findings or maternal age. The most common chromosome abnormality is complete monosomy X. The rare cases of mosaic and the one case of isochromosome mainly involve livebirths. Morphological analysis of foetuses revealed hygroma colli (84%) and hydrops (63%), frequently associated with major cardiac malformations. The livebirths present growth retardation, pterygium colli and facial dysmorphic features, but rarely complex malformations. In the light of our data, the probability of survival to birth is 0.8% and the prevalence in all clinical pregnancies is 1.1%.

We present a genetic and epidemiological study of trisomy 21 (T21) in the Canton of Vaud, the area covered by our local registry of congenital anomalies which has participated in EUROCAT Switzerland since 1988. During the period 1980-1996, we found 240 new T21 cases, all cytogenetically proven, out of 115,064 consecutive live births. Our purpose was to study trends and impact of biochemical screening and prenatal diagnosis of T21. We considered two different periods: 1980-1989 (before biochemical screening) and 1990-1996 (with screening) during which the mean maternal ages were respectively 28.4 years (10.6%or = 35) and 29.2 years (12.9%or = 35). The total prevalence of T21 was 2.08 per 1000; 5.4% of the cases were stillbirths, 49.6% were induced abortions and 45% livebirths. Prenatal cytogenetic diagnosis of trisomy 21 was performed in 52.1% of cases. Among women aged 35 or over the prenatal detection rates are superposable in the two periods. However, for younger women this rate has been much higher since the introduction of biochemical screening, i.e. 9.8% before and 51.8% after the introduction of triple test. In conclusion, the increase in prenatal diagnosis tests performed because of abnormal maternal serum marker levels has increased the global prenatal detection rate from 36.6% to 63.3% in our population, and the prevalence of Down syndrome has thus slightly decreased among livebirths.

We report a G-to-T de novo transversion mutation causing the substitution of a glycine with a cysteine (G375C) in a newborn with achondroplasia. This rare observation confirms allelic heterogeneity.

We report on a 6-year-old girl with C-trigonocephaly syndrome and diaphragmatic hernia. She is severely mentally retarded and shows the characteristic findings of this syndrome, including trigonocephaly, unusual facial features, especially intra-oral anomalies, low set and dysplastic ears, cardiac anomaly and neonatal hypotonia. Following our presentation at the 5th European meeting of dysmorphology in Strasbourg, P. Meinecke brought to our attention a case of C-trigonocephaly who died in the neonatal period from complications of a diaphragmatic hernia. Another case of C-trigonocephaly without diaphragmatic hernia was communicated to us by D. Lacombe. We report these three observations and present a review of 26 alleged cases.

Report of a family with dominant hereditary multicentric osteolysis. The review of the literature proves the clinical and genetic heterogeneity of the disease.

We report our results of a retrospective study of vesico-ureteral reflux based on the families of 66 index patients. The recurrence risk for sibs is 9,3%. With a prospective approach (ultrasound and uroradiology), the proportion of affected sibs is 26,6%. Our results are discussed with reference to the data of the literature.

Two brothers with a combination of atypical syndactylies, cerebellar atrophy and severe mental retardation are described. These cases share important features with the group of craniodigital syndromes and could represent new occurrences of Filippi syndrome. Cerebellar atrophy may represent a yet unreported finding in this syndrome.